Nonaerating apparatus for centrifugally purifying liquids



Nov. 17, 1925- S. H. HALL NONAERATING APPARATUS FOR CENTRIFUGALLY PURIFYING LIGUIDS Filed Oct. 1924 2 Sheets-Sheet l MWE/VTOR \Se/a en //a// JTTOR/VE Y8.

Patented Nov. 17, 1925.

UNITED STATES 1,561,784 PATENT, OFFICE.

sELDie-N 3.": HALL, or POUGHKEEPSIE, new YORK, ASSIGNOR TO THE DE LAVAL snmnnroa COMPANY, or NEW yoax, N. Y. A CORPORATION or NEW JERSEY.

NONAERATING-APPARATUS FOR CENTRIFUGALLY PURIFYING LIQUIDS.

Applieati on filed October 8, 1924. Serial No. 742,342.

accompany ng drawings, which form a part I of i this specification. c

It is well known to gce'ntrifuge tra nsformer, lubricating and other oils to remove from them water, 'dirt' and sludge. iVhen the purified'oil escapes from the rapidly revolving bowl, it. passes as a finely divided spray through a gas-filled space around the bowl discharge and inside the receiving covers. The gas in this space is ordinarily either'air, or a-mixture of,air,and oil vapor. In either case, the Oil becomes saturated with air. fChemists who have carefully investigated-the subject aver that centrifuged'oil actually takes into solution'as much as four per cent of oxygen and that this oxygen is :uractivengent in-causing the formation of sludge in the oil.

9 The objectionablencss of oil that has been contamniated with air is so well recognized that experts on the art of centrifuging have long sought to avoid this contamination.

Perhaps the most nearly successful expedient has been to make provision for the mamtenance of an atmosphere of CO 01' other inert gas in the space adjacent the oil discharge from the centrifugeand in the re; ceiving chamber; but this expedient, which has mitigated the evil somewhat, has not met with full success. I

My own researches have convinced me that success depends on the substantial exclusion of air or anyother gas from the oil during its assage from the transformer or other container for used oil, to and through the centrifuge and from the centrifuge Back to the container.

The revision of apparatus adapted to effect tiis result involves. something more than theinere arrangement of closed passages toward and from any centrifuge of known construction.

Thesol'ution of the problem in its mdst nearly perfect embodiment involves the provision of a special construction at the discharge neck of the centrifuge, the arrangement of passages to and from the centrifuge specially designed to exclude the admission of air to the system, provisions for establishing a super-atmospheric pressure in the discharge passage with which the centrifuge outlet for purified oil communicates, and provisions for excluding the leakage of oil from said discharge passage of the system.

A preferred embodiment of the invention is shown in the drawings. Figure l represents a complete centrifuging apparatus partly in elevation and partlyin section.

' Figure 2 is a'detailwiewpartly in section, of

part of the apparatus adjacent the bowl outlet, including particularly the discharge chamber, the bowl neck and its bearing, and the air andoil separatingchamber and connections thereto.

carries a valve e, by which the admission of oil from the feed pipe a into the cup-and from the cup into-the tube 9 is regulated, as hereinafter describedl The bowl proper It may be of ordinary construction andis not shownin its entirety, the drawing showing only the upper end portion of the tubular shaft 9 and the upper part of'the bowl shell, and its frusto-conical cover.

.The tube 11 for carrying water from the bowl discharges into a space surrounding the lower part of the neck Z of the bowl. 7' is a water discharge regulating ring. is is a water receiving cover.

On the upper extremity of the tubular bowl shaft 9 is screwed a bowl nut 79, which is held away from the bowl neck Z by buttons r,'so as to leave a discharge orifice s 'for discharge of purified oil.

Mounted on theinner edge of the upper shell of the water receiving cover is a cylindrieal extension n, which is secured, by means of a threadedn'ing 8, to an annular cover plate 9 threaded on the tube g. D0 pending froma flange on the extension u is a copper bellows '2) which flexibly supports a bearing 25 having a working fit around the bowl neck Z. A ring 23 supported from the cover is by two bolts (riot shown) underlies the bearing t.

The bowl h, in its normal operation, will oscillate rapidly with small amplitude. The

bearing t, by reason of its described flexible 1auspension, can follow the oscillations ofthe owl. a

The bellows v forms a surrounding fluidtight wall of a chamber 10 into which the oil discharges from the bowl neck through the orifice s.

The bowl neck Z has formed in its outer wall (see Fig. 2) two right-hand spiral 'grooves at m and n and an intermediate left hand spiral groove 0. In the bearing 15 are formed two annular chambers to and w.

' Spiral groove m communicates with chamchamber 00 in her to and extends upward therefrom.

Spiral groove 0 connects chambers w and w. Spiral groove n extends downward from chamberaz. v

A glass ]ar 11 (forming an Oll supplychamber and oil and air separating cham her) is located alongside the regulating cup 2. A w and opens into jar 11 just above its bottonu Another flexible tube 2 extends from to jar 11 and opens theremto near the top thereof. A wire gauge cup 13.

surrounds the upper endof tube .2. Cup 0' ply-pipe 66 leads. These ports are adapted 1 to be closed by. a plunger 18 on which is mounted a weight 19. The Weight 19 fits so closely within a cup 20 thatwhen the cup is filled with oil there is a strong dash pot action.

In operation, oil pumped from the container through pipe a enters the cup 0 through .port I) and flows from cup 0 through port into tube 9. During operation. the valve 0 is held up by the float d in position to open both ports. If oil tends to enter the cup 0 faster than the bowl can take and centrifuge it, the float (l rises and the valve 6 closes, or throttles, poi-t1) and so stops. or reduces, the inflow of oil. The inflow of oil will be altogether stopped before the cup overflows. If, on the other hand. the bowl tends to take and centrifuge oil faster than it is supplied to the cup through port I), the float and the valve'fall,

throttling port f so as toiprevent the 'indrawing of air.

flexible tube y extends from chamber At the narrow annulus between the float d and the wall of the cup, the surface of the oil is exposed to air, but the area of exposure is so limited and the oil at the exposed surface is so stagnant that the amount of air which it will dissolve is negligible.

From the tube 9 the oil flows into the bowl whereit is subject to the usual centrifugal separatingoperation. The water and dirt form an outer surrounding zone and the purified oil an inner central zone. The heavy dirt collects in a layer against the inside of the bowl shell. The water flows out through the tube i and escapes around the discharge control ring j into the cover is from which it is carried off by a spout (not shown).

The purified oil displaced toward the center of the bowl flows up the inside of neck Z out through the orifice 8 into the discharge chamber 10. From this chamber it passes through the pipe 15 and presses against the bottom of the plunger 18. When the predetermined pressure is reached, it lifts the plunger, opens port 17 and escapesthrough pipe 21 to the container for the oil.

The reason for maintaining-a super-atmospheric pressure in the oil discharge chamber 10 is that, otherwise air ill work iii between the bearing 15 and the bowl heck. I have found that 'an excess pressure of about six pounds to a square inch is suflicient to prevent this inward flow of air. However, with this pressure there is a tendency for oil to leak outward between the bowl neck and itsbearing. This tendency is counteracted by the right-hand spiral groove m. To be certain that it will fully counteract, the groove m is made large enough to pump some oil upward from the annular chamber to which, as hereinbeforestated, is connected, through pipe y, with the chamber 11.

The left-hand spiral .0 is made large enough to insure against entrance of air to chamber 10 and will 'pump some oil from no chamber w to annular chamber a; which, as

hereinbefore stated, is connected .through pipe .2 withthe upper part of chamber 11.

There is thus a restricted, but constant, endless circulation of oil from chamber 11, through pipe y, to chamber w; from chamber 10, through spiral groove 0, to-chamber a: and from chamber in back to chamber 11; and there is a slight diversion of oil from chamber 10 through spiral groove m.

oil in this chamber. The flow, l)O\VO\'3'-1',-b0

lngaway from chamber :r through pipe 2,

thisvmixture of air and oil passes into the tainer to the centrifuge and from thecentrifuge back to the container. There is substantially no contact between \the'oil' in the circuit and the atmosphere. There is no spray of oil from the centrifuge into a space whichis open to atmosphere or within which it is necessary to maintain a body of neutral gas, as the oil is discharged from the bowl into a discharge chamber from which is excluded access of alI fluids (liquid or gas) except the purifiedoil itself.v Ade quate provision is made to exclude the ad; mission of air and the escape of oil at'the point in the circuit where, without such provision, one or the other condition could necessarily occur.

- \Vhile I have stated that the purpose of the invention is to prevent the contamination of centrifugally separated mineral oil.

with air, it is obvious that the machine is adapted to be-ifse'd for separating any light liquid from any heavier liquids or solid material admixed therewith, where it is desired to prevent the absorption of air or any other foreign gas by such..lighter liquid.

While I have described the liquid as circulating from the container .for used-liquid,

or any other mixture to be separated, back chamber.

' tainer and back to the, container, a centrito the same container, it will be understood that the purified or separated liquid may be discharged intoa separate container, al-' though in that case it will be desirable to prevent access of air or other foreign gas into the receiving container.- Inasmuch, however, as the purified or separated liquid 1 will flew into. the receiving container in bulk and not in a'fine spray, as when discharged from the ordinary centrifuge, it

may be unnecessary, in some instances, to

take any precautions against contact between such liquid and air 'lIl'tlle receiving \Vhere in the claims I mean the word to be understood in its gen eric sense, and therefore to include atmospheric air, which, ordinarily, is the only contami'nating gas whose absorption by oil or other liquid that is being purified \or separated must be guarded against;

What I claim is:

1. In an apparatus forcentrifugally purifying liquids, the combination of a container for the contaminated liquid, means" providing a succession of passages from the con- 4k 77 speak of gas, It

fuge for purifying the liquid having. an inlet communicating with one of aid passages and' an outlet communicati g' with another of said passages, and means substantially closing said passages against ad mission of gas, thereby providing an endless circuit including the container and the centrifuge within which the liquid may be maintained uncontaminated by 'exteriorl'y present gas.

2. In the combination specified in claim 1 a valve interposed in thepassage between the centrifuge outlet and the container and v tending to close such passage and adapted .tobe operable by the pressure of the liquid flowing through siich passage to build up a superatmosph'eric pressure between it and the centrifuge outlet.

, 3. In an apparatus for purifyin liquids, the combination with a centrifuge Em separating a liquid fromits impurities by centrifugal force, the centrifuge having an outlet for the purified liquid, and means adapted to convey the contaminated liquid to the centrifuge, of a discharge passage communicating with the outlet from the centrifuge, said passage comprising walls one of which is flexible to allowfor the oscillation of the centrifuge.

4. In an" apparatus for purifying liquids, the combination with a centrifuge for separating a liquid from its .impurities by centrifugal force, the centrifuge having an outlet for the purified liquid, and means'ad'aptedf to convey the contaminated liquid to the centrifuge, of a discharge passage communieating with the outlet from the centrifuge, and means allowing oscillation of the bowl while maintaining said discharge passage sealed against admission of gas. 5. In an apparatus for purifying liquids, the combination with a centrifuge for separating a liquid from its impurities by centrif- -ugal force, the centrifuge having a neck through which the purified liquid is discharged from the centrifuge, 9f a discharge passage having walls closing said passage against leakage of gas thereinto,-the passage walls including a bearing inwhfich thebowl neck rotates and bearing.

6. In an apparatus for centrifugally purifying liquids, the combination with a centrifuge -bowlhaving ajneck and provided with an outlet for purified liquid, of a bearing in which said neck rotates, a discharge a flexible support for the passage communicating with said outlet and closedagainst admission of gas except between the bowlneck and'its bearing, and

means preventing leakage of gas between the two last named elements into the discharge passage.

7. Inan apparatus forcentrifugally purifying liquids, the combination with a centrifugal bowl having a neck and provided .ing away with an outlet for purified liquid, of a bearing in which said neck rotates, means adjacent the-bowl neck and its bearing providing a closed passage for receiving and carrythe purified liquid discharged from the bowl outlet, and means preventing leakage of gas between the bowl neck and its bearing into said passage.

8. In an apparatus for centrifugally purifying liquids, the combination with a centrifugal bowl having a neck and provided with an outlet for purified liquid, of a beara ing away the from the bowl ing in which said neck rotates, means adjacent the bowl neck and its bearing providing a closed passage for receiving and carrypurified liquid discharged outlet and means preventing the leakage of gas between the bowl neck 'away the purified liquid discharged from the bowl outlet, and means -to establish a super-atmospheric pressure in said passage to prevent leakage of gas thereinto through the bowl neck and its bearing. J

10. In an apparatus for centrifugally purifying liquids, the combination with a centrifugal bowl having a negk and provided with an outlet for purified'liquid, of a bearing in which said neck rotates, means adjacent the bowl neck and its bearing providing a closed passage f r receiving and carrying away the purifie liquid discharge from the bowl outlet, and means to estabmeans establishing communication between said source and said groove, thereby effecting a pumping of said liquid through said groove toward said passage and thus preventing leakage'of gas to said passage and leakage of liquid from said passage.

12. In an apparatus for centrifugallyw purifying liquids, the combination with a centrifugal bowl having a neck and provided with an outlet for purified liquid, of a bearing in which said neck rotates,meansv adjacent the bowl and its bearing providing a closed passage for receiving and carry ing away the purified liquid discharged from the bowl outlet, the bowl neck having 8 a spiral groove so directed that in the rotation of the bowl, any fluid in the groove will be pumped toward said passage, and the bearing having a chamber adapted to supply said groove.

13, In an apparatus for centrifugally purifying liquids, the combination with a centrifugal bowl having a neck and provided with an outlet for purified liquidfof a bearing in which said neck rotates, means adjacent the bowl neck and its bearing providing a closed passage for receiving and carrying away the purified liquid discharged from the bowl outlet, means to establish a super-atmospheric pressure in said passage to prevent leakage of gas thereinto through the bowl neck and its bearing, the

-bow1 neck having a spiral groove so d1-' lish a super-atmospheric pressure in saidv passage to prevent leakage of gas thereinto .through the bowl neck and its bearing, the

bowl neck having a spiral groove so directed that, in the rotation of the bowl any-fluid in the groove will be pumped toward saidpassage,

thereby counteracting the tendency of the liquid in the passage, due to the super-atmospheric pressure therein, to es cape between the bowl neck and its bearing. 11. In an apparatus for centrifugally purifying liquids, the combination with a centrifugal bowl having a neck and provided with an outlet for purified liquid, of a bearing in which said neck rotates, means adjacent the bowl neck and its bearing providing a closed passage for receiving and purified liquid discarrying away the outlet, the bowl neck having a spiral groove so directed that in get the rotation of the bowl any fluid in the groove will be pumped toward said passage, an auxiliary source of liquid supply,- and rooted that, in the rotation of the bowl, any fluid in the groove will be pumped toward said passage, an auxiliary source of liquid supply, and means establishing communication between said source and said groove, thereby effecting a pumping of said liquid 4 through said groove toward said passa e. 14. In an apparatus for centrifugaIly purifying liquids, the combination with centrifugal bowl having a neck and provided with an outlet for purified liquid, of

a bearing in which said neck rotates,

for receiving and carrying away the purified liquid discharged from the bowl outlet, and means to establish a super-atmospheric pressure in said passage to prevent leakage of gas thereinto through the bowl neck and its bearing, the bowl neck having a spiral groove so directed that, in the rotation of the bowl any fluid in the groove will be pumped towards said passage, the bearing having a chamber adapted to supply liquid to said groove. I j j 15. In an apparatus for centrifugally purifying liquids, the combination with a 1% centrifugal bowl having a neck and provided withan outlet for-purified liquid, of s a bearing in which said neck rotates, means. 'adjacent the bowl neck and its bearing providing a closed passage for receiving and means 110. adjacent the bowl neck and ltibBfl-Ilng providing a closed passage having a spiral groove so directed that, in

the rotation of the bowl, any fluid in the groove will be pumped toward said passage, the bearing having a chamber adapted to supply liquid to said groove, the-bowl neck having another spiral groove communicating with said chamber and sopositioned and directed as to'insure against the entrance of air to said chamber..

16. In an apparatus for centrifu'gally purifying 1i quids,t11e combination with ,a

a centrifugal bowl having a-neck and provided with an outlet for purified liquid, of a v bearing in which said neck rotates, means adjacent the bowl neck and its bearing providing a closed passage for receiving and carrylng ,away the purified liquid, discharged from the bowl outlet, the bowl neck having a spiral groove so directed that, in

the rotation of the bowl, any fluid in the groove will be pumped toward said passage,

the bearing having a chamber adapted to supply liquid to said groove, the bowl neck having another spiral groove extending in the opposite direction adapted to prevent entrance of air,to, and to pump liquid from, said chamber.

17, In an apparatus for centri'fugally purifying liquids, the combination with a centrifugal bowl having a neck and provided with an outlet for purified liquid, of a bearing in which said neck rotates, means adjacent the bowl neck and its bearing providin carrying away the purified liquid discharged from the bowl outlet, the bowl neck having a spiral groove so directed that, in the rotation of the bowl, any fluid in the groove will be pumped toward-said passage, the bearing having a chamber adapted to'supply liquid 'to said groove,-the bowl neck having a second spiral groove extending in the opposite direction and adapted to pump liquid fromsaid chamber, the bearing having a second chamber into which the liquid i is pumped from the second groove and means providing for circulation of li uid from the second chamber to the rst chamber.

18. In an apparatus for centrifugally purifying liquid, the combination with a centrifu al bowl having-a neck'and provided with an outlet for purified liquid, of a bearing in which said neck rotates, means ad'acent the bowl neck and its bearing providing a closed passage for receiving and I carrying away the purified liquid discharged from the bowl outlet, the bowl neck having a s iral groove so directed that, in the rota- 1 tion of the bowl, any fluid in the groove will be pumped toward said passage, the bearin having a chamber adapted to supply liqui y f to sa1d groove, the bowl neck having a adapts tolupply liquid to the grooves and 180 a closed passage for receiving and her and preventing escape of oiltherefrom between the bowl neck and the bearing. v 19. In an apparatus for centrifugally purifying liquid, the combination with a' centrifugal bowl having a. neck and rovided with an outlet fo purified liquid, of abearing in which sai neck rotates, means adjacent-the bowl neckand its bearing providing a closed passage for receiving and carrylng away thepurified liquid dischar ed from the bowl outlet, the'bowl neck having a spiral groove sodirected that, in the rotation of the bowl, any fluid in the groove will be pumped toward the said passage, the vbearing having a chamber adapted to supply-liquid tosaid groove, the bowl neck having a second spiral groove extending in the opposite direction and adapted to pump liquid from said chamber, the bearing having a second chamber into which the liquid is'pumped-from the second groove, the bowl neck having a third spiral groove extendin in the same direction as the first roove and communicating with the secon chamber and preventing escape of oil therefrom be- \tween the bowl neck and the bearing but a adapted to pumpairbetweeif the bowl neck and the bearing into the second chamber, means allowing circulation of liquid from thesecond chamber to the first chamber, and means operative during said circulation to release air mixed with the liquid flowing from the second chamber;

20. In an a paratus for centrifugal'ly.

and communicating withthe second'cham-b purifying liqui s, the combination with a.

centrifu al bowl having a neck and ro-' vided with an outlet for purifiedliqui of a bearing in which said neck rotates, means adjacent the bowl-neck and itsbearing providing a closed passage for receiving and fcarrylng away the purified liquid discharged from the bowl outlet, the bowl neck. having a s iral groove so vpositioned and directed t at, in the'rotation of the groove, it will, pump air from the atmosphere between the neckand its bearing, and means to divert such air away from between the neck and bearing toward the atmosphere. v 21. In an a paratus for 'centrifugally purifying liqui s, the combination of 'a discharge passage for purified liquid, a centrifugal bowl'having an outlet adapted to force Iiquidinto said discharge against pressure greater than atmospheric, the bowl neck ibly su' po bearm' having a chamber I purifying liquids,

a third adapted to pump air from the exterior (a; we

thus prevent access of air tothe upper end of the neck.

22. In an apparatus for centrifugally the combination with a centrifugal separating bowl having an outlet adapted to force liquid into a discharge chamber against a pressure greater than atmospheric and having a neck with three spiral grooves, of a flexibly supported hear ing surrounding the-neck and having an annular liquid supply chamber and an annular liquid escape chamber, one of said grooves being adapted to pump liquid from the supply chamber to the discharge chamber another adapted to pump liquid from the supply chamber to the escape chamber andthe to the escape chamber.

23. in an apparatus for centrifugally purifying liquids, the combination with a centrifugal bowl having a neck and provided with an outlet for purified liquid, of a bearing in which said neck rotates, means adjacent the bowl neck and itsbearing providing a closed passage for receiving and carrying away from the bowl outlet, means operative in the bowls rotation to pump from a point between said neck and bearing liquid, one toward said passage and theother in the opposite direction, and means providing passages for the return of the liquid in the second stream to said common point.

i 24. In an apparatus for ccntrifugally purifying liquids, the combination with a centrifugal bowl having a neck and provided with an outlet for purified liquid, of a bearing in which said'neck rotates, means adjacent the bowl neck and its bearing providin a closed passage for receiving and carrying away the purified liquid discharged from the bowl outlet, means operative in the bowls rotation to pump from a point between said neck and bearing two streams of liquid one toward said passage and the othe in the opposite direction, an auxiliary oi supply chamber, a pi e providing a passage for the how of liquid in the second stream to said chamber, and a pipe providing a passage forthe flow of liquid from said chamber to said point.

25. In the combination specified in claim 24,1neans to feed liquid to the centrifuge,

said means including a regulating cup, and a pipe connecting said cup and chamber and adapted to supply'liq'uidto the chamber.

26. In an apparatus for centrifugally purifying liquids, the combination with a centrifugal bowl having a neck and provided with an outlet for purified liquid, of a bearing in which said neck rotates, means adjacent the bowl neck and its bearing providing a closed passage for receiving and carrying away the purified liquid disthe purified liquid discharged two streams of and the other in the opposite direction and to pump air between the bearing and bowl to a point to which the second stream of liquid is pumped, means to circulate liquid from the second point to the first point, and means to release air from the liquid during its said circulation. i

27. In an apparatus for centrifugally purifying liquids, the combination with a centrifugal bowl having a neck and provided with'an outlet for purified liquid, of a bearing in which saidneck rotates, means adjacent the bowl neck and its bearing providing a closed passage for receiving an carrying away the purified liquid discharged from the bowl outlet, means operative in the bowls rotation to pump liquid from a point between toward said passage, ply chamber, an outflow pipe therefrom to said point, a feed for supplying to the centrifuge liquid to be purified, and a by-pass from said feed to said auxiliary liquid supply chamber.

- 28. lln an apparatus for centrifugally purifying liquids, centrifugal bowl having a neck and provided with an outlet for purified liquid, of a bearing in which said neck rotates, means adjacent the bowl neck carrying away the purified liquid dischar ed from the bowl outlet, means operative in the bowls'rotation to pump from a point between said neck and bearing two streams of liquid, one toward said passage and the other, in the opposite direction and to pump air hetweenthe bearing and-bowl "to a point to which the second stream of liquid is pumped, a liquid and air separating chamber, a pipe for mixed liquid and air leading from said secondpoint into the upper part of said chamber, outflow pipe from the lower point of said chamber to said first point';--

29. In the combination specified in claim 28, means providing an air vent from said chamber for air entrained with the liquid flowing through the first named pipe.

30. in an apparatus for centrifugallyand its bearing pro-, viding a closed passage for receiving and L admixture of fed thereto, a bearing said neck and bearing an auxiliary liquid supthe combination with a and a liquid purifying liquids, the combination with a v a centrifugal bowl having. a round neck rigid therewith, a non rotatable bearing adapted to fit-around the neck, a stationary member, and a metal bellows providing a flexible fluid-tight wall from said member to said bearing and permitting the bearing to follow the rapid oscillations of the bowl.

33. In an apparatus for centrifugally purifying liquids, the combination with a a cylindrical bowl having a neck and provided with an outlet for purified liquid,.of a bearing in which said neck rotates, and meansv adjacent the bowl neck and the bearing providing a closed passage for receiving the purified liquid discharged from the cen trifuge, said means including a fluid-tight flexible wall supporting the bearing.

34. In an apparatus for centrifugally purifying liquids,.the combination witha cylindrical bowl having a neck and provided with an outlet 'for purified liquid, of

a bearing in which said neck rotates, .and means adjacent the bowl neck and its bear- 6 I I I mg providing a closed passage for recelving.

the purified liquid discharged from the cen- -trifuge,.said means including a metal bellows providing a flexible support for the bearing.

35. In an apparatus for centrifugally purifying liquids, the combination with a centrifugal separating bowl having a neck through which the purified liquid is discharged, of means to feed liquid. to said bowl and to control the feed to prevent overflow thereof and substantial contact of air therewith, a passage adapted to receive the purified liquid discharged from the bowl and having a liquid outlet but otherwise closed, means on said outlet to cause the pressure in said passage to be greater than atmospheric, a bearing around the neck of the bowl, means to supply liquid to said bearing relatively near the liquid discharge end of said neck, means for escape of liquid from said bearing relatively distant from the liquid discharge. end of said neck, means on said' neck tending to-cause a flow from said supply means toward the liquid discharge end of said neck and toward the esicape means and means tending to cause a flow of fluid from the end of the bearing most' distant from the liquid discharge end of the neck toward the escape :means.

In testimony of which invention, I have hereunto set my hand, at Poughkeepsie, New York, on this third day of October,

.SELDEN H. HALL. 

